With the Siege of Petersburg stretching into its second month, Gen. Ulysses S. Grant sought to weaken the Confederate defenses by making a demonstration northward, toward Richmond. Late on the night of July 26, 1864, and into the next morning, Gen. Winfield S. Hancock crossed the James River with the Union Second Corps and two divisions of Gen. Phil Sheridan’s cavalry. Gen. Robert E. Lee responded by sending two divisions to meet the threat, reinforcing the Confederate lines at New Market Heights and Fussell's Mill. On July 28, the Confederates launched a counterattack against Sheridan's men near the Darby house. The following night, July 29, the Hancock recrossed the river leaving a garrison to hold the bridgehead at Deep Bottom.